The central air conditioning is not working in my rental in Aurora, CO Thanks, -Darren

Those are to very good areas that have seen great improvements over the last five years.

I live in FL so I know about having to use A\C year round.As you know people mention a brand and price but not model which will ultimately determine the total cost.I was in the exact same situation and due to the rusted coil tubing, and overall condition of the Air Handler decided for a total A\C replacement.Payne is considered "Builders Grade" lowest grade and some A\C guys argue not to install them because it reflects on their reputation when you have problems with the system.Look for the highest seer rated, quietest, best warranty HVAC that is fairly priced.The installer is a HUGE part of the HVAC's life span, along with your regular changing filters, cleaning coils when needed, cleaning drain lines and vacuuming dust out of the Air Handler Cabinet.

Our weather hits all the extremes, I think most good quality people expect cent/heat & air.  

The tenant pays every month, keeps the inside very clean, not just maintains the lawn but has improved it far beyond its state when he moved in, and never complains about frivolous stuff.  

All units are as originally built and nothing has been replaced or improved (including HVAC).

I currently work full time as an air traffic controller and looking for opportunities to generate active and passive income through rental properties, flips, wholesales, etc.

We are doing all the requisite cosmetic fixes and hope to sell next year for a good profit, through the market is soft so we may need to rent for a year and see if it starts to improve.

There is limited appreciation upside and you should keep that in mind when contemplating what improvements to make to the property.  

Then I got a call from my tenant at 7:30 this morning that the air wasn't working again.